Thank You all!
I was confused by the fact that someone said that he had this feature on Oneplus 3.
So...
I hope we will have this in nearest future.
Have a nice day!

Hello!
I've not been to this forum for a long time.
I already had some experience with ubuntu on my Oneplus One and also on Oneplus 3.
Then there were some video playback issues (though not only that).
I am talking about the MP4 format.
On Oneplus 3 video was not played at all.
And only short video (approximately 5-10 minutes) was played on Oneplus One.
So questions to Ubuntu Touch users of all smartphone models:
Does your smartphone model play 50+ min or 500+ MB video?
Please give me an answer in the format like:
My model is ... - the problem with the video is the same as yours
or
My model is ... - I have no problems with the video.
Thank You All in advance.
Kyrylo.

@slowcyclist Thank You very much!

I've just copied and pasted some of lines from your topic and USB-tethering WORKS NOW!!!
(I don't know why )
Here are that commands:
$ sudo android-gadget-service enable rndis
$ sudo bash /android/system/halium/usr/share/usbinit/setupusb reset
$ sudo bash /android/system/halium/usr/share/usbinit/setupusb rndis
$ sudo ifconfig rndis0 up
$ sudo tethering enable

Please, test it sombody else with Oneplus3.

@Lakotaubp
Yep!
I can mistaken, maybe order should be different.
I've just messed up with those commands and suddenly it worked.